14
Infrared Noise
As mentioned earlier, Infrared Noise includes all environmental disturbances that occur when the
sensor is not detecting a target, such as wind chill on stationary objects or blowing tree leaves on
moving objects. Much of this type of disturbance is “filtered” out by the side-by-side orientation of
the infrared beams. Thus, heat rising from a blacktop road will hit both beams simultaneously,
causing a cancellation of their signals. However, under certain circumstances, a tree branch
moving back and forth as the wind blows can look like a person doing the same thing. This can
really be a problem if the sensor is aimed at the tree trunk, which is relatively warm due to
sunlight, and the cooler leaves from a branch are blowing across it. Or a blade of grass located a
few inches from the sensor, blowing in the wind, can also “appear” as a person walking, again
because of the smaller beam geometry at that distance.
To prevent unwanted false alarms or reduced sensor performance, the sensor should always be
located on a stationary object (large tree trunk), which will not move when the wind blows (avoid
smaller diameter trees). Any offending grasses or branches should always be pruned away from
the sensor’s field of view. Avoid aiming the sensor at trees with moving branches, especially at
close distances (less than 100 feet). Better results will be obtained if you aim the sensor at open
spaces or bushes that are more solid in mass. Also, at close distance (20 feet or less), you
should use the IR-903 and program the sensitivity to a low value (value 1 or 2).
RF INTERFERENCE
This device complies with part 15 of the FCC rules (FCC ID RVL-SICSAW916). Operation is
subject to the following conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received, including interference that may cause
undesired operation.
When operating in an urban area, sources of interference can include 900 MHz cordless phones,
spread spectrum phones, computers, and other data transmission devices. Interference caused
by these sources is usually of limited range (100 ft.) due to the fact that the FCC restricts the
power output at this frequency. The presence of interference is indicated by a flickering
Red LED
when the Receiver Processor is first turned on (Range Test/Walk Test Mode). Although the
Receiver Processor will reject most of this interference, it is best to locate the interfering source
and remove it (if possible) prior to doing installation, or degraded reliability could result.
Warning: This device operates under Part 15 of the FCC Rules. Any modification not expressly
approved by IntelliCam, LLC may void the warranty and the user’s authority to operate this
device.
